The present invention relates generally to plow assemblies adapted to ride on the surface of a conveyor belt and, more particularly, to such plow assemblies which include a plow which is capable of rotation about a vertical axis and preferably is capable of vertical movement relative to the belt.
While the present invention will be discussed hereinafter with reference to its use in conjunction with a conveyor type filtering device used for dewatering of sludge, it should be recognized that its use and applicability are not thereby so limited.
Belt-type filtering devices used for the dewatering of sludge generally comprise an endless, liquid permeable conveyor belt supported in a generally horizontal position by a perforate guide table. Sludge is deposited on the horizontal belt at one end of the device and as the belt travels along the guide table, water continually passes through the perforate belt to yield a dewatered sludge at the other end of the device.
It has been found that dewatering in such a device is facilitated if one or more so-called "plows" are arranged above the belt to extend into the moving sludge and contact the upper surface of the belt. Such plows tend to evenly distribute the sludge over the surface of the belt, help prevent the formation of solid material layers, and also tend to keep the perforations in the belt open by scraping over or wiping the top surface of the belt.
To prevent an accumulation of solid matter on the plows, it has been one practice to have the plows pivotally mounted on the filtering device such that the plows pivot upwardly out of the sludge upon such accumulation. While such an arrangement may be satisfactory for some purposes, the amount of scraping and wiping action by the plows is dependent upon the interrelationship among the weight of the plow, the density of the sludge and the speed of the belt. Thus, for a given plow, the wiping or scraping action may vary considerably as the operating conditions of the device change.